The present invention pertains to a device for holding a crystal block in a crystal pulling arrangement, wherein a vertically displaceable pulling shaft that contains cooling channels for a cooling medium is provided with a seed crystal holder, on which a crystal neck of smaller diameter and a crystal block of larger diameter are formed during the pulling of the crystal block.
When pulling crystal blocks, a problem arises in that the size of the crystal block being produced is limited by the crystal neck of smaller diameter which is initially formed on the seed crystal holder. If the crystal blocks become excessively large and consequently excessively heavy, the crystal neck is no longer able to hold the crystal block, i.e., the crystal neck fractures. In order to eliminate this problem, the crystal block being formed could conceivably be supported by a carrying device that engages on the outer surface of the crystal block. However, this is associated with certain technical difficulties because the carrying device can only be utilized once a sufficiently long crystal neck is formed. In addition, it needs to be ensured that the carrying device does not exert forces upon the crystal block transverse to its longitudinal axis which could lead to fracturing of the crystal neck.
An object of the present invention is therefore to develop a device for holding a crystal block which initially allows an unobstructed pulling of the crystal block and subsequently supports the crystal block of larger diameter, without introducing lateral forces into the crystal block.